The proposed study is a national survey of blood exposure among all major occupational groups of non-hospital health care workers. The long term objective is to prevent infection from blood-borne pathogens, including HIV, hepatitis B, and hepatitis C, by characterizing the extent of exposure to blood-borne pathogens among non-hospital health care workers, developing an understanding of the risks of blood exposure, and contributing to development of effective intervention strategies. Specific aims are to (i) estimate the incidence of blood exposure among non- hospital health care workers engaged in patient care, (ii) identify and quantity risk factors for exposure, (iii) quantify availability and use of preventive measures (including those related to use of safety devices, training, reporting, and equipment) and their impact on exposure incidence, and (iv) identify potential strategies for prevention intervention efforts in non-hospital settings. The primary study design is a retrospective nationwide mall questionnaire survey of physicians (surgical and non-surgical), physician assistants, nurses (RNs and LPNs), palliative and home care nurses and nurse-midwives, dental workers, phlebotomists, and emergency medical technicians. The study population will consist of a stratified random sample of workers in each occupation. The primary sampling frame will be stratified by occupation and by whether or not states require use of safety devices. Large sample sizes will permit (a) derivation of national estimates of blood exposure incidence by occupational group and setting (e.g., clinics, long-term care facilities, emergency medical services, correctional facilities, and home health care), (b)comparison of overall blood exposure incidence among non-hospital health care occupations in states with and without safety legislation, (c) quantiflcation of risk factors and availability and use of preventive measures by occupation and setting, and their impact on exposure rates, (d) comparison of incidence, risk factors, and use and availability of safety measures with those for hospital health care workers, and (e) identification of potential strategies for reducing exposure and infection. This survey will be supplemented by a survey of the management of a subsample of institutions in which the respondents work, to examine the effect of institutional factors (e.g., reporting mechanisms, safety training programs) on blood exposure. The management survey also will be used to (a) characterize management policies, procedures, and practices, including training/education, reporting, provision of safety equipment and medical safety devices, and pro and post-exposure prophylaxis, (b)validate responses from the workers' survey on availability and use of preventive measures, and (c) characterize management knowledge and attitudes regarding prevention of exposure.